Cameron Diaz and Sean “Diddy” Combs are bonding over more than just a “movie project” — they were caught kissing Saturday night at PH-D at the Dream Downtown Hotel. Spies said the blond actress, who split with Yankee slugger Alex Rodriguez in September, started the night off with dinner at Marble Lane in the lobby with friends. Afterward, the group migrated upstairs to PH-D, where Diddy came to meet Diaz at her table at about 1:15 a.m. After the music mogul ordered multiple bottles of Ciroc, Grey Goose and Patrón, onlookers said Diaz and Diddy were attached to each other all night. “They were kissing and making out,” and continued being “very affectionate” while they danced, our sources said. Diaz and Diddy left the club together with the group just after 3 a.m. This isn’t the first time Diaz has been seen fiddling with Diddy. A Page Six spy saw the pair canoodling over lunch at Scarpetta in Beverly Hills last month following an earlier dinner at Meatpacking District hot spot Catch. But Diaz’s rep insisted at the time they were discussing a movie project. Her rep still maintains, “They are friends and are not dating.” Diddy’s rep echoed that the two are “just friends.”